Parabola-forming device.



K. E. JOHNSSON.

PARABOLA 'ronmme DEVICE.

APPLICATION FILED FEB. I3, 1917.

1,291,01 1. Patented Jan. 14, 1919.

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K. E JOHNSSON. PARABOLA FORMING DEVICE.

APPLICATION FILED FEB. 13. 1917.

Patented Jan. 14, 1919.

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I IKN'UT EMIL JOHNSSON, OF WILKINSBUBG, PENNSYLVANIA. v

PARABOLA-FORMING DEVICE.

Specification of Letters Patent.

Patented Jan. 14, 1919.

Application filed February 13, 1917. Serial No. 148,394.

To all whom it may concern:

Be it known that I, KNUT E. JoHNssoN, a subject of the Kin of Sweden, residing at 332 Pitt street, Wil insburg, in the county of Allegheny and State of Pennsylvania,

have invented new and useful Improvements -1n Parabola-Forming Devices, of which thefollowing is a specification.

This invention has reference to means for defining or evolving a parabola, and has particular bearing upon a device of this character primarily operable for metal working devices.

One of the main objects of the invention resides in an attachment for an ordinary turning lathe, whereby through the use of the attachment an accurate and predetermined parabolical cut or mark may be formed upon work carried by the lathe.

Another object of the invention is to provide a simple and efiicient device of the above character, which will be capable of being readily connected with a lathe, or with other mechanisms, wherein is embodied adjustable features of construction which will enable the same to define parabolas of varying dimensions.

To this end, the invention consists of a system of articulated arms which are adapted to be connected with the tail stockof an ordinary lathe and with. the tool slide of such a lathe, so that uponthe lateral movement of the tool slide, the joints of the arms, which arms have connection with the tail stock, travel in an arc while the joint or joints connected with the tool slide will move on a straight line. The effect of this movement is transmitted to the arms in a novel manner so that the tool governing element carried thereby will always remain equally spaced with respect to the said joints. The movement imparted to the elements will be of a parabolical nature and by connecting the element with a cutting or stcnciling tool, the movement of said element will, therefore. be synchronously transmitted to the said The extent or proportion of the curve defined by the tool may be conveniently regulated by adjusting the tail stock todifferent positions relative to the slide. In other words, an object of the invention is to provide novel means for operating on metallic and other surfaces for accurately forming or shaping the. same to true parabolic orm.

With the foregoing and other objects in pivot 9, and the levers 6 view, the invention consists in the details of construction, and in the arrangement and combination of parts to be hereinafter more fully set forth and claimed.

In describing the invention in detail, reference will be had to the accompanying drawings forming part of this specification, wherein like characters denote corresponding parts in the several views, and in which Figure l is a. fragmentary top plan view of the lathe illustrating the application of the present invention thereto;

Fig. 2 illustrates a similar view showing the invention in a different position from that shown in Fig. 1;

Fig. 3 is a side elevation with the parts in the position disclosed in Fig. 1;

Fig. 4 is a transverse sectional view, the plane of which being indicated by the line 44 of 15 Fig. 5 is a similar view taken along the line 5-5 of Fig. 2; and

. Fig. 6 is a diagrammatic view illustrating a slightly difl'erent application of the present invention.

As shown in the drawing, the invention is shown mounted upon a lathe 1, a fragmentary portion only of which is shown. As illustrated, it comprises a bed 2, a tail stock 3 and carriage 4, which elements are suflicient to show the applicability of the invention to lathes now in common use.

The parabola forming device 5 comprising the present invention includes a series of levers 6, 6, 6" and 6, the levers 6 and 6 having ends connected b the pivot 7, the levers 6 and 6 having t eir adjacent ends connected by the pivot 8, the levers 6 and 6 having their adjacent ends connected by the and 6 having their adj acent ends connected by the pivot 10.

The pivots 7 and 9 are provided with upwardly extended portions 11 and 11 respectively, and thesaid extensions are provided with apertures 7" and 9 respectively, for the reception-of bars 13 and 13, which slide in the apertures for a purpose to be presently explained.

e inner ends of the bars are connected by a coupling14 and the said coupling has a vertically disposed pivot 15.

The pivot 8 has an upwardly extending portion 11 having an aperture 11. therein for the reception of a sliding rod 16 and the said rod is slidable in a sleeve 17. which is carried by or projects from the upwardly extending portion 11. The inner end of the sliding rod is mounted on the ivot 15 of the coupling 14:. The outer end 0 the sleeve 17 is secured in a cylindrical block 18 carried upon the outer end of the plunger 19 of the tail stock 3. The tubular sleeve 17 s slidable in an opening 20-formed in the said block 18 and may be secured at difierent positions of adjustment by the set screw 21. Although Fig. 5 illustrates a detailed construction or arrangement for fastening the block to the plunger of the tail stock, I do not wish to be limited with respect to this arrangement.

A tool slide is mounted to move freely transversely of the carriage 4 and the pivot 10 is fixed or attached to it so that as the arms 6? and 6" articulate, it communicates movement to the said tool slide, which movement is longitudinally of the lathe bed 2.

The carriage 4: may be moved transversely of the lathe bed by means of the operating crank 23 which is the usual means provided in lathes for eiiecting this result. The tool rest 24 has a tool 25 clamped by the tool post 26 to the tool rest and these elements may be of any ordinary construction and while the illustration is more or less diagrammatic, it is thought that one skilled in the art will understand the application of the tool, tool post and parts associated with them to the tool rest. The tool rest is mounted to slide freely longitudinally of the tool slide and it has a seat or socket 27 for the reception of a shank 28 of the arm 29, which arm is pivotally connected to the coupling 14, being mounted on the pivot 15 of said coupling, and the said arm has its shank adjustable with relation to the tool rest and it is held at dififerentpositions of adjustment by the set screw 30.

Themechanism described comprises certain elements, the functions of which have been stated in connection with a description of said elements, but in order to convey an understanding of the correlation of parts and the manner in which they contribute to the intended result, it is believed that a description of the operation of parts in producing a device having a parabolic surface will be helpful.

In operation, the dimensions of the parabola to be formed is first determined, and the shank 28 and the rod 16 are adjusted to correspond thereto. It will be apparent from the foregoing description that the parts which are pivotally connected to the block 18 swing about the said pivot in an arc, while the parts which are connected by the pivot 10 to the tool slide 22 move in substantially a straight line. The carriage is, through the medium of the handle 23, moved until the pointoi the tool 25 is at the edge of the area which is to be formed naeinii into .a parabolical surface. As the carriage is conveyed transversely of the lathe bed 2, the tool will, through the medium of the hereinbefore described parts, be caused to advance longitudinally of the lathe upon a true parabolical curve. Inasmuch as the construction insures the constant. maintenance of a point at the center of the pivot 10 and a pointat the center of the pivot 8 equi-distant at all times from the coupling 14:, this being due to the jointed connections existing between the linear moving tool slide slide 22 and the are described by the mechanism swinging about the block 18. This results in imparting a parabolical movement of the coupling 1a which, in turn being attached to the tool rest 24., will impart a similar movement to the tool 25 carried thereby.

The pivot 10 in this operation travels in a substantially straight line transversely of the lathe bed while its cooperating pivot 8 oscillates on an arc struck from the block 18 and this variance of movement is comensated for bythe provision of the pivots and 9 oscillating upon the rods 13.

In the modification shown in Fig. 6. provision is made for evolving or forming a parabola having a more pronounced curve and in carrying out this embodiment of the invention, a wheel or disk 32 may be rotated by a worm 33, turned by the crank handle 34:. In this form, I employ a tool rest 2%, a carriage 4:, an arm 29' connected to the tool rest, and I employ arms 6, 6 6 and 6, which are connected by pivots 7, 8, 9 and 10 and I also employ a coupling ll having rods 13, 13, slidable in u wardly extending portions of the pivots and 9, their inner e'nds'being secured to the coupling 14?. The construction of the coupling 14 and the parts connected with it may be the same as that shown in connection with the disclosure in Figs. 1 to 4 inclusive, there being a connecting rod 16 slidable in a sleeve 17, which sleeve is oscillatably mounted on the post 18 and these parts are intended to operate for producing a parabolical curve, according to the operations herein described.

The manner of communicating motion to the coupling 1 for increasing the-movement of the tool, includes a bar 35 which is connected to a dish or wheel 32 by fas-' tenings such as 38, the said disk or wheel being mounted on a shaft 37. The bar 35 is pivotally connected to a link 36 and the link in turn may be mounted on the pivot corresponding to the pivot 15 in Fig. 2. The pivot l0 connecting the bar and the links allows the bar to oscillate and permit movement of the link which may also oscillate on the pivot corresponding to the pivot 15 of the form shown in Fig. 4:. The dis tance between the center of the shaft 3'? and the center of the pivot 40 should be twice the focal distance of the parabola being formed. The bar 35 can be adjusted on the disk or wheel 32, so that the apparatus can be set to vary the length of the block from the center ofl the sha 37 to the center of the pivot 40. Where this construction is employed, the arc described by the ivot 40 will not vary greatly from the para ola described by the coupling 14' with the result that the latter will be moved substantially parallel to the side? of the slide 4 In operating this modified ap aratus, the worm 33 and the element 14. wi lbe forced at nearly equal angles to the bars 16 and 29 and by means of that, the power on the slide 4? and rod 16 will be parallel to their guides.

From the foregoing description, it will be seen that there is provided mechanism in which the objects of the invention may be achieved, and that the advantageous features above mentioned aie among others present. The device is relatively simple in construction and the embodiments disclosed herein are supplied only for illustrative purposes and it is not the intention of the inventor to be limited with respect to the "means for when oscillated to carrying the invention into eflect.

I claim:

1. A device for evolving a parabola, consisting of a system of members arranged in substantially quadrangular formation, said members having their adjacent ends overlapped and pivotally jointed, a means for moving a joint of'said members on a substantially straight line and to thereby oscillate the said members about a common center, and a tool governing element spaced equi-distantly between the straight mo joint and a swinging joint, and adapted definea parabolical curve.

2. A device for evolving a parabola, consisting of a system of cobperating members arranged in substantially quadrangular formation, said members having their adjacent ends overlapped and pivotally jointed, a means for movin a joint of said members on a substantial? straight line, and to thereby oscillate te said members about a common center, a tool-governing element spaced equidistantly between the straight moving oint, and a swinging joint, and adapted when oscillated to define a parabolical curve, a means'for connecting said element with an operating tool, whereby the movement of the element will be directly transmitted to said tool;

3 A device for evolving a parabola, eonsistmg of a system of arms arranged in substantially quadrangular formatiomi said arms having their adjacent extremities overlapped and pivotallye jointed, one of the joints of said arms ing mounted upon a movable body for. linear movement, and a second joint mounted upon a relatively stationary body for arouate movement, and a tool-governing element associated with said joints, and operable to maintain the same relative distance therebetween, irrespective of the positions bf the joints.

4. A device for evolving a parabola, consisting of a. plurality of pivotally joined arms, one of the joints of said arms being movable on an arc, and a second joint movable in a substantially straight line, and

rods cobperating with said joints and eX-.

tending to a common center, a casing for connecting the extremities of said rods at the said center, whereby the casing will be maintained equidistantly spaced between the swinging joint and the straight moving joint, substantially in the manner described.

5. A device for evolving a parabola, consisting of pivotally joined arms defining a quadrangle, one of the joints of said arms bemg arranged to oscillate on an arc, and the supporting a cobperating side to a relatively stationary body, and a tool controlling element carried by said frame andso associated withthe latter that the element will remain in substantially equally spaced relation with the supported side of said arm in all positions of the latter, and means for transmitting the movement of said element to an operating tool.

7. A parabola evolving device, comprising an articulated-frame, adjustable means carried by one side of said frame for pivot ally supporting the latter upon stationary object, means for swiveling an opposite side of said frame to a body capable of movement in a linear direction, a tool operating element supported between and by the joints of said frame, a ways maintain the center of frame,

a relatively a position substantially in the supported sides of said and means for directly transmitting the movement from the said element to an operating tool upon the linearly movable body. a

8. In a parabola evolving device, the combination with a'lathe provided with'a tail fstgck and a surface slide, an articulated operation of the and operable to having one side. pivotally and ad-j justably supported by the tail stock, means i for -swiveling. an opposite and cobperating side of the frame to the surface slide for linear-movement, and a tool governing element synchronously movable with the frame when the surface slide is operated, and capable of describing a parabolical curve, and means for transmitting the movement of said element to an operating tool.

9. A device for cutting a parabola comprising the combination with a rod mounted to be oscillated about a fixed pivot but allowing said rod to slide through said fixed pivot, a tool slide, a tool rest, a tool carried thereby, and means said rod, tool slide and tool rest operable to cause the point of the tool to describe a parabola.

10. The combination with a tool slide, a tool rest, a tool carried thereby, means for moving the tool slide away from a surface to be-treated, means coacting with the first mentioned means for simultaneously movin the tool rest toward a surface to be treated, means moved on a fixed pivot forcontrolling the means for moving the tool slide, and means slidable with relation to the fixed pivot and oscillatably with relation to said fixed pivot for controlling the tool slide.

L 11. In combination with a tool slide and a tool rest, atool carried thereby, means for moving said slide and rest simultaneously cooperating with LQQLGH toward and away from a surface to be treated, means moved on a fixed pivot for controlling the means for moving the tool slide, and means slidable with relation to the said fixed pivot and oscillatable with relation to said fixed pivot for controlling the tool slide, and means for imparting movement to said means to carry them transversely of the surface to be treated.

12. A device for cutting a parabola consisting of a plurality of arms, each of said arms being pivotally connected to two other arms to form a substantially quadrangular structure, means for maintaining two 01 the opposite pivots in alinement, a member carried by the alining means, means for guiding said member in a curve about a fixed pivot, a tool, a tool rest, an arm secured thereto pivotally connected to the said memher, a tool slide having one pivot of the quadrangular structure connected to it, a sliding device connected to the member and slidable in the means for guiding the structure in a curve, and means for moving said tool, tool rest and slide across the face of the Work.

In testimony K. Eli UL JOHNSSUN.

whereof I afidx my signature. 

